The fuel triangle (behind the cockpit) is there Peter. Look very closely, and you'll see the shape, which appears darker than expected, and almost lost in the highlight. It may be a red 'C3' triangle. The other markings below the windscreen are the oll and grease instructions.
At this stage of the war, the main stencils were normally maintained after a re-paint, or the addition of such things as a mottle.
There might have been an exception where the yellow (or white) distemper paint was applied to the cowlings, where these markings could be overpainted with the washable paint. However, many (general) photos show these still in place too.
I think I'd add all of the main stencils, such as the frame numbers, wing walk lines etc., as these were normally re-applied fresh, when the aircraft was re-painted from the original dark colours to the 'winter' scheme with the RLM 65 up the fuselage sides. Fuel markings, and oxygen markings, were fastidiously maintained, especially where two types of fuel were available.
It's looking bl**dy good so far mate !